The present technology relates to the technical field of a wiring board and a manufacturing method of a wiring board. Specifically, the present technology relates to the technical field for improving flip-chip connectability and preventing occurrence of chipping in an IC (Integrated Circuit) chip by forming a laminate that is obtained by laminating a plurality of insulating layers and a plurality of wiring layers between a first stiffener and a second stiffener and thereby suppressing occurrence of warping.
Along with the recent speed-up and high performance of electronic components (IC chips) used as microprocessors, or the like of a computer, the number of terminals tends to increase and pitches between terminals tend to be narrow. Generally, a large number of terminal parts are provided on the bottom of an IC chip in an array form.
Such terminal parts of an IC chip have a large difference in pitch with respect to connection terminals formed on a circuit board that is called a mother board, and thus it is difficult to mount the IC chip on the mother board.
Thus, in order to connect the IC chip to the mother board, a wiring board that is called a semiconductor package is formed, the IC chip is mounted on (connected to) the wiring board, then the wiring board is mounted on (connected to) the mother board, and thereby the IC chip is connected to the mother board via the wiring board.
As such a wiring board described above, for example, there is a so-called coreless type wiring board configured by a laminate that is formed by laminating a plurality of insulating layers and a plurality of wiring layers using a build-up method (for example, refer to Japanese Unexamined Patent Application Publication No. 2002-26171). In such a coreless type wiring board, the length of the entire wiring is shortened by omitting a core board, transmission loss of high frequency signals is reduced, and accordingly, the IC chip can be operated at a high speed.
However, since the coreless type wiring board does not have a core board, the thickness thereof decreases, causing a difficulty in securing high rigidity, and finally, warping easily occurs.
On the other hand, there is a core type wiring board configured in such a way that a plurality of insulating layers and a plurality of wiring layers are laminated on both faces of a core board so as to form a laminate on a wiring board and the core board and the laminates are thereby integrated (for example, refer to Japanese Unexamined Patent Application Publication No. 2008-124124). The core type wiring board has an advantage that general rigidity is higher than that of a coreless type wiring board, and accordingly warping diminishes when a core board is included.